Protesters wave Syrian revolutionary flags during a demonstration at al-Hamra neighborhood in Homs, Syria, Friday, May 11. A Syrian opposition leader said Friday the regime is trying to destroy a UN-brokered peace plan for the country.

Washington — The suicide bombings that killed at least 55 people in Damascus Thursday reveal the shambles made of a key argument for Western nations to approve the UN cease-fire plan for Syria.

By that reasoning, sending international monitors into the country and giving the cease-fire a chance would eventually make anti-interventionist powers like Russia and China more open to international action.

But if anything, reactions to the bombings revealed a deepening split among world powers on the subject of Syria. With Russia attacking the forces arrayed against the regime of President Bashar al-Assad, and the United States finding a way to blame the Assad regime, prospects for any consensus that would allow more forceful international intervention appeared dimmer than ever.

The twin car bombings in busy morning traffic also raised the specter of Al Qaeda’s entry into the Syrian conflict. It was not the first bombing in Damascus bearing the signature marks of the extremist Islamist organization, but the massive coordinated attack strengthened concerns in the US and elsewhere that Al Qaeda might be taking advantage of Syria’s unrest to infiltrate the country (possibly from Iraq) and target the Assad regime.

In response to the bombings, Russia was quick to reiterate its thinking that some members of the international community are going so far as to promote violence as a means of subsequently justifying international intervention. “Some of our foreign partners are taking steps to ensure, both literally and figuratively, that the situation explodes,” Russian Foreign Minister Sergei Lavrov said while on a visit to Beijing.

At the other end of the spectrum, the Obama administration said Assad was at least indirectly to blame for the bombings for having allowed Syria’s political uprising to fester and more recently for failing to implement the six-point cease-fire plan of former UN Secretary-General Kofi Annan, which calls for an end to all violence and steps towards political reform.

“If the Assad regime were doing what it’s supposed to do, which is to lead the way in demonstrating its commitment to the cease-fire, then we think that that would set the tone and we would not be seeing these kinds of violent episodes elsewhere in the country,” said State Department spokeswoman Victoria Nuland. “It is the Assad regime that created this climate of violence that is causing not only folks to take up arms in defense, but is also providing an environment, potentially, for mischief to be made by others who don’t favor peace in Syria.”

Terrorism experts note that the Assad regime defeated Islamist militants who were gaining strength in the country in the 1980’s, and say that this time the regime’s preference for repression over reform in the context of the Arab Spring is favoring the rise of Al Qaeda and other extremist elements. Some add that while Al Qaeda did not know initially how to respond to the region’s clamor for democracy and freedom, it has proved adept at exploiting extended political instability.

The Arab Spring has “upset the balance in a way that Al Qaeda can take advantage of” in places like Syria and even Libya, says Juan Zarate, a former terrorism specialist in the George W. Bush White House. Drawn-out conflicts like Syria’s provide “more space ideologically for Al Qaeda and Al Qaeda-like individuals to operate,” added Mr. Zarate, speaking recently at a conference sponsored by the Washington Institute for Near East Policy.

Still, it remains far from clear what impact hardening evidence of Al Qaeda’s involvement in Syria would have on prospects for international intervention.

One reason the Obama administration has remained tepid about sending more robust assistance – including arms – to the Syrian opposition, is the speculation that some factions of the opposition include elements of Islamist militancy. On the other hand, the US would be unlikely to sit by if a key Middle Eastern country like Syria showed signs of becoming an Al Qaeda operating ground.

With Russia and China showing no signs of bending in their total opposition to any kind of foreign intervention, action might eventually come in the form of some variation of a “coalition of the willing,” but even that seems far off. Even though the Annan cease-fire plan appears to be on life-support, some 200 additional international monitors are scheduled to arrive in Syria by the end of May.

The Pentagon is drawing up contingency plans for different intervention scenarios, including air cover for “humanitarian corridors” or for safe zones where the opposition could take refuge from battling Assad, Secretary of Defense Leon Panetta told reporters this week.

But the Obama administration appears to see no good options for Syria and so is disposed to letting the Annan plan die a slow death.

Another key factor to consider: Last year when Libya was in turmoil and civil war threatened, it was then-French president Nicolas Sarkozy who pressed the US and NATO to intervene militarily on the side of the opposition. This year Mr. Sarkozy has been defeated, and there is no other Western leader jumping into his shoes and fervently making the case for intervention in Syria.